Add version info from git-describe

A new script, gen-version.sh, is now invoked from 'make version' to generate
the file VERSION. This file contains a version identifier generated by
git-describe and is included in the Makefile.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.c

@@ -8,9 +8,6 @@
 
 #include "cgit.h"
 
-const char cgit_version[] = CGIT_VERSION;
-
-
 static int cgit_prepare_cache(struct cacheitem *item)
 {
 	if (!cgit_repo && cgit_query_repo) {